The lessons that I've learned over the years. You need to very cautious that the patients are not on any kind of anticoagulant, aspirin, Advil, any other of the nonsteroidals including. These patients will bleed if you give them reason to so you need to make sure that their clotting studies are normal and that they're not on any type of anticoagulants. In our business we need to make sure there's no distal obstruction, and in the biliary business I assume the same is true. We do routine follow-up imaging. Just because a patient feels better, we don't assume that everything is better. It is possible to induce PVC's and V-tach with shock waves. If you shock wave right on the heart you definitely will do that and especially the right upper pole of the kidney and the gallbladder is in the neighborhood. We generally administer the shock waves not gated, meaning that with no relationship to the EKG. As soon as we see one PVC, however, we tell the anesthesiologist to stop and we gate the machine. The machine is then gated to the QRS complex so that the shock wave is never delivered on the T-wave and in that way no further arrhythmia will be induced. It slows you down a little bit because with the non-gated you're going at 110 shocks per minute, with the gated shock wave lithotripsy it's whatever the patient's rate is and invariably it'll happen when the patient's on beta blockers and so you're going at about 50 a minute and you're standing there twice and three times as long as you normally would, but you need to do that for the patient's safety.
You do not need to put these patients under general anesthesia. Sedation is sufficient. We've worked this out very well and the patients get Versed and Fentanyl or Alfentanil, and you'll see when we do the patient today that she'll be very comfortable through the whole thing.